This invention relates to extruded cellular thermoplastic polymer foam useful for both sound absorption and thermal insulation end uses.
Polymer foams having desirable sound absorption properties are well known. Many are also known that are made of thermoplastic materials. However, one of the drawbacks in using thermoplastic polyolefin foams is that they generally not suitable for both acoustic absorption and thermal insulation. Acoustic absorption is generally considered to require the use of open celled foams or a combination thereof a macrocellular foam, while thermal insulation is generally considered to require closed cell foams or microcellular foams. The open celled foams are considered to be at a further disadvantage in environments exposed to water, because they tend to absorb water, lowering their thermal insulating value even more.
Therefore, there is still a need for improved thermoplastic polymer foam materials capable of such dual use, especially for wet environments.